1. Technical Field
The present invention relates to an in-vehicle instrument control device, and particularly to an in-vehicle instrument control device that controls a power source of a plurality of in-vehicle instruments.
2. Related Art
Conventionally, control of a power source of in-vehicle instruments provided in a vehicle has been performed by operating an ignition switch or a power switch that collectively switches a state of the power source of the respective in-vehicle instruments. For example, when the ignition switch is set to OFF, the power source of almost all the in-vehicle instruments is turned off, and when the ignition switch is set to ACC, the power source of a part of the in-vehicle instruments is turned on, and when the ignition switch is set to ON, the power source of almost all the in-vehicle instruments is turned on.
Accordingly, for example, when a car stereo device, a car navigation device, or the like is used, in order to supply power to those in-vehicle instruments, the ignition switch needs to be set to ACC or ON. As a result, the power source of the in-vehicle instruments that are not used is also turned on, thereby causing wasteful power consumption.
Moreover, conventionally, there has been proposed a technique in which a connection switch is interposed between a navigation ECU and an air-bag ECU, and a battery, and when code verification by an ID code sent from an electronic key succeeds, the relevant connection switch is turned on to supply the power to the navigation ECU and the air-bag ECU (e.g., refer to Japanese Unexamined Patent Publication No. 2004-25938).
Accordingly, even though the ignition switch or the power switch is not operated, the supply of the power to the navigation ECU and the air-bag ECU is started almost at the same time as unlocking of a door lock of the vehicle using the electronic key, which can bring about a usable state.
However, in this case, after the code authentication has succeeded, the power continues to be constantly supplied to the navigation ECU and the air-bag ECU. This will cause power consumption even when a user does not use the navigation ECU.